Services such as phone communications, television, position search, short-range communications, hands-free communications are provided to portable wireless apparatuses that are widely used in recent years, the portable wireless apparatuses having functions for supporting the services.
The services described above are provided in communication systems such as GPS (Global Positioning System, 1.5 GHz band), Bluetooth (2.5 GHz band) representing short-range wireless communications and digital television broadcasting (470 to 740 MHz).
Aside from the above-described communication systems, communication systems for mobile phones in Japan include PDC (Personal Digital Cellular, 800 MHz band/1.5 GHz band) and the third generation mobile communication systems (2 GHz) representing W-CDMA (Wideband Code Division Multiple Access).
Furthermore, communication systems for mobile phones in countries other than Japan include GSM (Global System for Mobile, 800 MHz band), DCS (Digital Communication System, 1.8 GHz band) and UMTS (Universal Mobile Telecommunications Systems, 2 GHz band).
If a portable wireless apparatus has an application for supporting various communication systems, it is necessary that the portable wireless apparatus have a structure with a plurality of antennas resonating in frequency bands of various communication systems.
It is known that a conventional portable wireless apparatus, which deals with the abovementioned problems, has an extendable antenna and a folding antenna connected with each other to operate over a frequency band of digital television broadcasting (refer to Japanese Patent Laid-Open Publication No. 2004-228665 (Patent Document 1)).
It is also known that an antenna device has a case with first and second conductor plates mounted therein to form a dipole feed arrangement and to thereby operate over a wide frequency band. The antenna device operates over a low frequency band since the second conductor plate has a meander shape (refer to Japanese Patent Laid-Open Publication No. 2004-208219 (Patent Document 2)).
It is known that a dipole antenna is constituted by elements different in shape from each other, as shown in FIG. 14, and provided as an unsymmetrical antenna in a foldable case to resonate over a wide frequency band as shown in FIG. 15. (refer to Non-Patent Document “Hokuriku-section Joint Convention of Institutes of Electrical Engineering in 2004, CP-41.”    Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-228665    Patent Document 2: Japanese Patent Laid-Open Publication No. 2004-208219    Non-Patent Document 3: Hokuriku-section Joint Convention of Institutes of Electrical Engineering in 2004, CP-41